* View and specifications as reconstructed at 1934-35. Aircraft as in the largest known Air Group ever carried (during the Pearl Harbor raid).

Kaga was laid down on 19 July 1920 at Kawasaki Heavy Industries shipyard as a Tosa class battleship. On 5 February 1922 both Tosa class ships were canceled and designated for scrapping under the terms of the Washington Naval Treaty, but Kaga was therefore selected for completion as an aircraft carrier, instead of battlecruiser Amagi, damaged beyond repair in the earthquake in 1923. The conversion of Kaga was launched in 1925 and completed on 31 March 1928.

As completed, the ship had two hangar decks, the hangars opened onto two superimposed flying off decks at the bow. In theory, this per­mit­ted aircraft to take off directly from the hangars, while landing on the main flight deck above. In practice, the multiple flight deck ar­ran­ge­ment proved unsuccessful. From 1934 to 1935, Kaga received a massive reconstruction at Yokosuka Naval Dockyard. There the hull was lengthened, the hangars extended forward, the flying off decks removed, the power and aircraft capacity increased and an island super­struc­ture on the starboard side of the ship added.

Kaga was active off China during the next few years. During the opening stages of the Pacific War, she took part in the attack on Pearl Harbor, the invasion of Rabaul, the attack on Darwin, the Indian Ocean raids, and the battle of Midway, where she was hit by four bombs at 1023, 4 June 1942. The hits caused massive fires and secondary explosions among fully fueled and armed aircraft on the hangar decks. Three and a half hours after the attack the crew was ordered to abandon Kaga. The doomed ship was scuttled by torpedoes from her escort destroyers at 1925, 4 June 1942, at position 30°23' N 179°17' W.